Knee Care Quiz

The knee joint is the junction of three bones: the femur (thighbone or upper leg bone), the tibia (shinbone or larger bone of the lower leg) and the patella (kneecap), which sits over the other bones at the front of the knee joint and slides when the leg moves. Four ligaments connect the femur and tibia and brace the joint against abnormal movement. The ligaments are the anterior cruciate ligament (ACL), the medial collateral ligament (MCL), the posterior cruciate ligament (PCL) and the lateral collateral ligament (LCL). Separating the bones of the knee are pads of connective tissue called menisci. They act as shock absorbers, cushioning the lower part of the leg from the weight of the rest of the body, as well as enhancing stability.

Changing direction or twisting rapidly, slowing down when running and landing from a jump are often the causes of injury to the anterior cruciate ligament. Injuries to the medial collateral ligament usually are caused by blows to the outside of the knee. The posterior cruciate ligament can be injured by a blow to the front of the knee.

The meniscus – the cartilage that sits between the femur and the tibia and acts as a shock absorber – can be torn by twisting, cutting, pivoting, slowing down when running or being tackled. The kneecap can be injured or pushed out of alignment by trauma, overuse or poor muscle strength.

Kneecap problems also can be caused by not warming up properly and by poor muscle strength in the hamstrings or quadriceps.

Being overweight can put more stress on knee joints, because the knees are the primary support for body weight.

Your health care provider may need to treat these injuries early.

These can occur when you do too much, too soon or when you try to push through pain.

Putting weight on a knee and then twisting or bending it in an abnormal direction can tear ligaments or damage the cartilage.

It most often affects middle-aged and older people. Osteoarthritis may be caused by repeated injury to the knee, excess weight or a deformity of the knee joint.